33 research outputs found
The (2√3×3)rect. phase of alkylthiolate self-assembled monolayers on Au(111): a symmetry-constrained structural solution
Low-energy electron-diffraction (LEED) patterns of the Au(111)(2√3×3)rect.-butylthiolate surface phase (a structure also seen in longer alkane chain thiolate self-assembled monolayers) show missing diffracted beams characteristic of glide symmetry, but do not show the larger set of missing beams found in surface x-ray diffraction (SXRD). The difference can be attributed to the greatly enhanced role of multiple scattering in LEED, but the combination of symmetry constraints placed on possible structural models by the observed SXRD and LEED beam extinctions greatly reduces the number of possible structural models. Only three such models are identified, one of which is clearly incompatible with other published experimental data. The relative merits of the remaining models, both involving Au adatom-thiolate moieties, are discussed in the light of the results of previous experimental studies
The local adsorption site of methylthiolate on Au(1 1 1): Bridge or atop?
Measurements of the local adsorption geometry of the S head-group atom in the Au(1 1 1)(√3 × √3)R30°–CH3S surface have been made using normal incidence X-ray standing waves (NIXSW) and S 1s scanned-energy mode photoelectron diffraction on the same surface preparations. The results confirm that the local adsorption site is atop an Au atom in a bulk-continuation site with a S–Au bondlength of 2.42 ± 0.02 Å, and that there can be no significant fraction of coadsorbed bridging species as recently proposed in a combined molecular dynamics/experimental study by Mazzarello et al. [R. Mazzarello, A. Cossaro, A. Verdini, R. Rousseau, L. Casalis, M.F. Danisman, L. Floreano, S. Scandolo, A. Morgante, G. Scoles, Phys. Rev. Lett. 98 (2007) 016102]. The results do not, however, clearly distinguish the different local reconstruction (adatom) models proposed for this surface
IN VITRO ANTI-DIABETIC AND ANTI-OXIDANT ACTIVITIES OF ETHANOL EXTRACT OF TINOSPORA SINENSIS
Objective: The aim of the present study was to evaluate the alpha (α)-amylase and alpha (α)-glucosidase inhibitory activities and in vitro antioxidant activities of the 80 % aqueous ethanol extracts of Tinosporasinensis Lour (Merr.).Methods: The 80% aq. ethanol extract of the plant was prepared. The plant extract was examined for its antioxidant activity by using free radical 1,1-diphenyl-2-picryl hydrazyl (DPPH) scavenging method, ABTS radical scavenging ability, reducing power capacity, estimation of total phenolic content, flavonoid content and flavonol content. Different concentrations (2, 4, 8,10and 15 μg/ml) of the extract was subjected to α-amylase inhibitory and α-glucosidase inhibitory activities and IC50were calculated.Results: The study revealed that the different concentrations of the plant extract possessed a very good amount of total phenolics, flavonoid and flavonol and exhibited potent radical scavenging activity using DPPH and ABTS as a substrate. The ethanol extracts exhibited significant α-amylase and α-glucosidase inhibitory activities with an IC50 value1.093µg and 1.04µg dry extract respectively and well compared with standard acarbose drug.Conclusion: Thus, it could be concluded that due to the presence of antioxidant components the plant extracts could be used for the treatment of hyperglycemia, diabetes and the related condition of oxidative stress. This knowledge will be useful in finding more potent components from the natural resources for the clinical development of antidiabetic therapeutics
Reply to Comment on 'Local methylthiolate adsorption geometry on Au(111) from photoemission core-level shifts'
A reply to the Comment by Albano Cossaro et al
Kramers turnover in class of thermodynamically open systems: Effect of interplay of nonlinearity and noises
A system-reservoir nonlinear coupling model has been proposed for a situation
where the reservoir is nonlinearly driven by an external Gaussian stationary
noise which exposes the system particles to a nonequilibrium environment. Apart
from the internal thermal noise, the thermodynamically open system encounters
two other noises that are multiplicative in nature. Langevin equation derived
from the resulting composite system contains the essential features of the
interplay between these noise processes. Based on the numerical simulation of
the full model potential, we show that one can recover the turnover features of
the Kramers dynamics even when the reservoir is modulated nonlinearly by an
external noise.Comment: 7 pages, 2 figure
Novel Microbial System Developed from Low-Level Radioactive Waste Treatment Plant for Environmental Sustenance
A packed bed bioreactor efficiently treated low-level radioactive waste for years with a retention time of 24 h using acetate as the sole carbon source. However, there was generation of dead biomass. This bioreactor biomass was used to develop a bacterial consortium, which could perform the function within 4 h while simultaneously accumulating nitrate and phosphate. The dead mass was negligible. Serial dilution technique was used to isolate the world’s first pure culture of a nitrate accumulating strain from this consortium. This isolate could simultaneously accumulate nitrate and phosphate from solution. Its ability to form biofilm helped develop a packed bed bioreactor system for waste water treatment, which could optimally remove 94.46% nitrate within 11 h in batch mode while 8 h in continuous mode from waste water starting from 275 ppm of nitrate. The conventional approach revealed the strain to be a member of genus Bacillus but showed distinct differences with the type strains. Further insilico analysis of the draft genome and the putative protein sequences using the bioinformatics tools revealed the strain to be a novel variant of genus Bacillus. The sequestered nitrate and phosphate within the cell were visualized through electron microscopy and explained the reason behind the ability of the isolate to accumulate 1.12 mg of phosphate and 1.3 gm of nitrate per gram of wet weight. Transcriptome analysis proposed the mechanism behind the accumulation of nitrate and phosphate in case of this novel bacterial isolate (MCC 0008). The strain with the sequestered nutrients work as biofertilizer for yield enhancement in case of mung bean while maintaining soil fertility post-cultivation
The misasandry myth: An inaccurate stereotype about feminists' attitudes toward men
In six studies, we examined the accuracy and underpinnings of the damaging stereotype that feminists harbor negative attitudes toward men. In Study 1 (n = 1,664), feminist and nonfeminist women displayed similarly positive attitudes toward men. Study 2 (n = 3,892) replicated these results in non-WEIRD countries and among male participants. Study 3 (n = 198) extended them to implicit attitudes. Investigating the mechanisms underlying feminists’ actual and perceived attitudes, Studies 4 (n = 2,092) and 5 (nationally representative UK sample, n = 1,953) showed that feminists (vs. nonfeminists) perceived men as more threatening, but also more similar, to women. Participants also underestimated feminists’ warmth toward men, an error associated with hostile sexism and a misperception that feminists see men and women as dissimilar. Random-effects meta-analyses of all data (Study 6, n = 9,799) showed that feminists’ attitudes toward men were positive in absolute terms and did not differ significantly from nonfeminists'. An important comparative benchmark was established in Study 6, which showed that feminist women's attitudes toward men were no more negative than men's attitudes toward men. We term the focal stereotype the misandry myth in light of the evidence that it is false and widespread, and discuss its implications for the movement